Beliefs that influence cost-related medication non-adherence among the “haves” and “have nots” with chronic diseases

John D Piette¹, Ashley Beard¹, Ann Marie Rosland¹, Colleen A McHorney^2
1Ann Arbor VA Healthcare System, Ann Arbor, MI, USA and the University of Michigan Medical School, Department of Internal Medicine, Ann Arbor, MI, USA; ²US Outcomes Research, Merck and Co, Inc, North Wales, PA, USA

Background and objective: Some patients continue taking their medication as prescribed despite serious financial pressures, while others with the ability to pay forego treatment due to cost concerns. The primary goal of this study was to explore how patients' beliefs about the necessity of treatment and treatment side effects, influence cost-related non-adherence (CRN).
Methods: 27,302 participants in the Harris Interactive Chronic Illness Panel completed an internet survey. The current study focused on two subsamples representing: (a) the most economically-vulnerable survey respondents (ie, individuals with household incomes of US$25,000 per year or less and monthly out-of-pocket medication costs of at least US$60, n = 1321); and (b) respondents who were the most likely to have the financial resources to pay for medications (ie, those with incomes of US$125,000 or more and monthly medication costs of less than US$60.00, n = 1195). Multivariate models were constructed for each group to determine the independent impact on CRN of perceived need for medications and side-effect concerns. Increased risk for CRN associated with depression and asthma diagnoses also was examined.
Results: Twenty-one percent of economically vulnerable respondents reported continuing to take their medication as prescribed despite serious cost pressures, while 14% of high-income respondents reported CRN despite apparently manageable out-of-pocket costs. Both low perceived need for medications and concerns about side-effects affected CRN risk in low-income and high-income groups. Within groups of both low-income and high-income respondents, depression and asthma significantly increased patients' odds of reporting CRN.
Conclusion: Beyond objective financial measures, CRN is influenced by patient beliefs, which can influence the perceived value of prescription drugs. Addressing these beliefs, as well as the unique adherence concerns of patients with depression and asthma, could decrease CRN rates even if cost pressures themselves cannot be reduced.

Keywords: medication adherence, cost-of-care, access to care, chronic disease